set_task_blocker · Vaiz MCP: Risk & Policy

WHAT IT DOES

What set_task_blocker does on Vaiz MCP

AI agents use set_task_blocker to create or update resources in Vaiz MCP — usually the action step of a workflow, after the agent has gathered context. Every call changes real data in your Vaiz MCP environment.

WHY IT NEEDS A POLICY

Why set_task_blocker needs a policy

This tool modifies task relationships (blocker status) which is a reversible change to data state. It does not delete or destroy data (not Destructive), does not execute arbitrary code (not Execute), involves no financial operations (not Financial), and creates/modifies rather than merely reading (not Read).

From the tool's definition Tool name contains 'set_task_blocker' and description indicates it 'Toggle[s] a blocker relationship between two tasks', which modifies task metadata relationships in a reversible manner.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

set_task_blocker Rate-limited

set_task_blocker stays usable, but capped — an agent stuck in a loop can't make hundreds of changes a minute. Everything else on the server is denied unless you say otherwise.

View as policy code

policy.json

{
  "version": "1",
  "default": "deny",
  "tools": {
    "set_task_blocker": {
      "limits": [
        {
          "counter": "set_task_blocker_rate",
          "window": "minute",
          "max": 30,
          "scope": "grant"
        }
      ]
    }
  }
}

LIMIT THIS TOOL →

Instant setup, no code required.

PolicyLayer is an MCP gateway: every tool call is checked against your rule before it reaches Vaiz MCP, so you can run agents against it safely.

FAQ

Questions about set_task_blocker

What does the set_task_blocker tool do? +

Toggle a blocker relationship between two tasks. Direction is relative to taskId:. It is categorised as a Write tool in the Vaiz MCP MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.

How do I enforce a policy on set_task_blocker? +

Register the Vaiz MCP server in PolicyLayer and add a rule for set_task_blocker: allow, deny, rate-limit, or require approval. Point your MCP client at the PolicyLayer proxy URL and the rule is enforced on every call, before it reaches Vaiz MCP. Nothing to install.

What risk level is set_task_blocker? +

set_task_blocker is a Write tool with medium risk. Write tools should be rate-limited to prevent accidental bulk modifications.

Can I rate-limit set_task_blocker? +

Yes. Add a rate_limit block to the set_task_blocker rule in your PolicyLayer policy. For example, setting max: 10 and window: 60 limits the tool to 10 calls per minute. Rate limits are tracked per agent session and reset automatically.

How do I block set_task_blocker completely? +

Set action: deny in the PolicyLayer policy for set_task_blocker. The AI agent will receive a policy violation error and cannot call the tool. You can also include a reason field to explain why the tool is blocked.

What MCP server provides set_task_blocker? +

set_task_blocker is provided by the Vaiz MCP server (vaizcom/vaiz-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.